exhaust

[396chevy]

hello everyone i want to put in a exhaust system {89 350 4x4} ie headers,cat muffler dual pipes out. now my question is long headers or short, do i need a new y-pipe, what kind of cat i heard monolithic {or something like that} is best should i have the system welded together or can i clamp it?what size pipe 2/2.5 ect. what brand of headers gives most power. do underdrive systems really work? do high performance tbi/high lbs injectors work? and how much power r we talking about?do cold air intakes really work i cut the baffle out of my stock system. does anyone know about anything else to get that extra few horses? sincerly 396chevy

[scottie]

okay... first of all, i have flowtech shorties for headers, i never did too much research into 'em cause i got these for real short money from my friend. decent performance enhancement with those, im happy. i also have a hiflow dynomax cat, i hate those huge, heavy stock cats.
as for pipe size id say 2.5" and 3" tail pipes after the muffler (that produces a real good sound) and absoloutly have it welded, i highly recommend that.
cold air intakes and other high performance intakes will work well with an aftermarket, performance exhaust.
As for the extra horsepower, id recommend one of those computer chips. and if your feeling really ambitious, you cant go wrong with a superchanger!